19987

Appears in sequences

• Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MFS = ZSM-57 H1.5[Al1.5Si34.5O72] starting with a T2 atom.at n=13A019176
• Numbers k such that gcd(3k,8^k+1) = 3 but k does not divide the numerator of B(2k) (the Bernoulli numbers).at n=30A070193
• a(n) = a(n-1) - a(n-2) + a(n-3) + a(n-4), a(0)=4, a(1)=1, a(2)=-1, a(3)=1.at n=38A073937
• Reflected tetranacci numbers A073817.at n=38A074058
• Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, -1), (-1, 0, 1), (0, 1, -1), (1, -1, 0), (1, 1, 1)}.at n=8A149616
• a(n) = prime(n)*T(n), where T = A000217.at n=21A196421
• The number of tilings of a 5 X (3n) floor with 1 X 3 trominoes.at n=6A236576
• Number of set partitions of [n] such that the difference between each element and its block index is a multiple of six.at n=23A274839
• Number of partitions of n which can themselves be subdivided into two partitions whose sums differ by 1 at most.at n=37A276107
• Number of non-equivalent ways to place 5 non-attacking ferses on an n X n board.at n=5A278684
• Triangle read by rows T(n, k) = number of non-equivalent ways to place k non-attacking ferses on an n X n board.at n=42A278688